another electrical question

[pete64]

All of my interior lights are out with the exception of the rear dome lamp and the exterior light that also houses the third brake light. These both work as designed. Looking at this drawing

https://docs.google.com/open?id=0B6N...3RYTmdPSmxVR1E

the common thread is the ground at G200. Problem with that theory is the lamps that work also use that ground connection. Also the map lights are out and it appears that they use a different ground so G200 is not a factor in that. The other common point is of course power but again the lights that don't work are in common with the lights that do.

So the question is has anyone experienced a similar situation or possible found that the grounds in fact are isolated from one another. Also what exactly is the left cowl panel so I can get behind it and check G200.

[Mikey350]

I'm pretty sure that G200 is behind the RIGHT (passenger side) kick panel. G201 is behind the LEFT kick panel (where your parking brake is).

[Steve83]

"Cowl panel" = "kick panel"; the plastic trim on the side of the footwell, forward of the door. Just because one thing is still grounded, that doesn't mean that EVERYthing at that location is. Inspect - don't stop at analysis. And don't assume that everything is still put together exactly the way it was designed over 20 years ago. Is the truck a museum piece? Create a DETAILED signature with all the truck's specs using the info in this caption:

[pete64]

yes I understand things get monkeyed with and I'm dealing with that now but everything so far has been obvious. It seemed really odd to me that the grounds would all be brought back to a central location when they could ground them locally at many of the fixtures. Figured I'd ask for a sanity check on what the diagram was telling me before I spent hours chasing this gremlin. Hopefully I'll have an answer to this mystery tomorrow. That is if I get the chance to look at it as I'm may be putting together the 351 for my Son's 86.

[pfun41]

Originally Posted by pete64

yes I understand things get monkeyed with and I'm dealing with that now but everything so far has been obvious. It seemed really odd to me that the grounds would all be brought back to a central location when they could ground them locally at many of the fixtures. Figured I'd ask for a sanity check on what the diagram was telling me before I spent hours chasing this gremlin. Hopefully I'll have an answer to this mystery tomorrow. That is if I get the chance to look at it as I'm may be putting together the 351 for my Son's 86.

What makes you think it's the grounds? There's a connector at the bottom of the B pillar behind the trim that is for the dome lamp. Its in a spot where water likes to collect in leaky trucks and is susceptible to corrosion.On my 90 one of the wires had corroded and broken off that connector and the map lights wouldn't work.

[wdford]

Originally Posted by pete64

yes I understand things get monkeyed with and I'm dealing with that now but everything so far has been obvious. It seemed really odd to me that the grounds would all be brought back to a central location when they could ground them locally at many of the fixtures. Figured I'd ask for a sanity check on what the diagram was telling me before I spent hours chasing this gremlin. Hopefully I'll have an answer to this mystery tomorrow. That is if I get the chance to look at it as I'm may be putting together the 351 for my Son's 86.

Grounds are better off at a common location, it's easier to troubleshoot. Also can you imagine your truck full of holes for ground straps everywhere? NOw you've only 1 location to search for loose studs or corrosion. Besides every component may not be near an adequate ground source.

I love to oversimplify but have you checked for power at the sockets? Did you get a good solid voltage within -.5v of the battery? You'd be testing the socket with a different ground source too.

[miesk5]

yo, Check the ckts in this 92 wiring diagram
Notice the splices.

& as PFUN ADVISED;
Dome Connector Corrosion in Driver's Side B Pillar pic; "...This is a picture of the connector behind the driver side seat belt retractor. This is a common area of problems. On mine, the wires had corroded and fell out of the connector. .... wire had corroded on the connector and preventing power getting to the dome light..."

Source: by Jem270

Dome Connector in Driver's Side B Pillar pic in a 95
Source: by quinault @ http://fullsizebronco.com/forum/showthread.php?t=172775

test courtesy light door Jamb switches

[pete64]

Finally got some time to work on the 95 (been spending most of my free time on the son's 86) and found the dome light issue. As I originally assumed the ground for the dome and map lights does not return to a central location as the wiring diagram says but it relies on a ground locally. The PO loved to take things apart and put them back together with self tapping screws but he failed to replace the screw which provided the ground to the lights.

I've still got electrical gremlins though. While installing the ground screw I slipped and blew the fuse. After that the power locks and keyless entry quit working. I hear the relays click when I hit door switch but the locks don't move. No idea how those are related as that circuit is supposedly fed off a cb that also feed a bunch of other stuff that still works. I didn't have any fuses or a way to the parts store at the time and didn't get very far in the Bronco as the trans was in limp home mode. Apparently the dome light fuse also feeds the speedo so the trans lost VSS.

So I'll be replacing the fuse tonight, and making sure I have spares, and we'll see what is what. The lights in the doors still don't work so I've still got issues but the dome light is fixed.

[Mikey350]

The RKE (remote keyless entry) system has connections all throughout the interior (and some exterior) courtesy lights. I have some schematics that might help. Take a look at these and the schematics before and after it:

http://www.supermotors.net/registry/media/900442


Good Luck

[Steve83]

.

[pete64]

yep replacing the fuse fixed all my problems. Well except the door lamps but that could be bulbs. What I don't get is why I could hear relays clicking when trying to lock/unlock the doors but nothing happened. Clearly the power to the locks comes from the keyless entry module and without the fuse it would not function but it would seem to be the relays would be downstream of this module.

No matter it's fixed now and I know what the deal is going forward.

Thanks for the help!!

[Steve83]

The clicking you heard wasn't necessarily the factory lock relays inside the RKE module. Pull that fuse & try to pinpoint the source.